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Query: EC:3.1.3.1 (
alkaline phosphatase
)
47,916
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Intestinal ischemia necessitates rapid re-establishment of blood flow to prevent irreversible anoxic tissue damage. However, reperfusion results in additional injury as a consequence of the generation of oxygen free radicals. To date, no clear-cut marker to differentiate between
ischemia
versus reperfusion injury is available. In this regard, previous studies from our laboratory utilizing a rat in vitro lipid peroxidation model demonstrated that the generation of free radicals resulted in the inactivation of only the intestinal brush border
alkaline phosphatase
enzyme, with no effect on other membrane-bound digestive enzymes. Current studies were designed to assess the possibility of
alkaline phosphatase
being a specific marker of the reperfusion injury in canine and human ex vivo
ischemia
/reperfusion models. Small bowels harvested from canines and organ donors were subjected to
ischemia
followed by reperfusion. Brush border membrane enzymes,
alkaline phosphatase
, sucrase, maltase, and gamma-glutamyl transpeptidase were assayed in mucosal extracts from intestines with
ischemia
versus reperfusion. In both experimental models, there was no change in any enzyme activity with warm
ischemia
alone. In contrast,
alkaline phosphatase
activity was significantly decreased in both the canine and human reperfusion models, with no change in specific activities of sucrase, maltase, and gamma-glutamyl transpeptidase. Our data indicate that the
alkaline phosphatase
enzyme activity may represent a potential marker of intestinal reperfusion injury and may permit quantitative assessments of therapeutic interventions in human intestinal reperfusion injury.
...
PMID:Decrease in mucosal alkaline phosphatase: a potential marker of intestinal reperfusion injury. 1021 63
A gene therapy strategy involving direct myocardial administration of an adenovirus (Ad) vector encoding the vascular endothelial growth factor 121 cDNA (Ad(GV)VEGF121.10) has been shown to be capable of "biological revascularization" of ischemic myocardium in an established porcine model [Mack, C.A. (1998). J. Thorac. Cardiovasc. Surg. 115, 168-177]. The present study evaluates the local and systemic safety of this therapy in this porcine
ischemia
model and in normal mice. Myocardial ischemia was induced in Yorkshire swine with an ameroid constrictor 21 days prior to vector administration. Ad(GV)VEGF121.10 (10(9) or 10(10) PFU), Ad5 wild type (10(9) PFU), AdNull (control vector with no transgene; 10(9) PFU), saline, or no injection (naive) was administered in 10 sites in the ischemic, circumflex distribution of the myocardium. Toxicity was assessed by survival, serial echocardiography, blood analyses, and myocardial and liver histology at 3 and 28 days after vector administration. All pigs survived to sacrifice, except for one animal in the Ad(GV)VEGF121.10 (10(10) PFU) group, which died as a result of oversedation. Echocardiograms of Ad(GV)VEGF121.10-treated pigs demonstrated no differences in pericardial effusion, mitral valve regurgitation, or regional wall motion compared with control pigs. Intramyocardial administration of Ad(GV)VEGF121.10 included only minimal myocardial inflammation and necrosis, and no hepatic inflammation or necrosis. Only a mild elevation of the white blood cell count was encountered on day 3, which was transient and self-limited in the Ad(GV)VEGF121.10 group as compared with the saline-treated animals. As a measure of inadvertent intravascular administration of vector, normal C57/BL6 mice received intravenous Ad(GV)VEGF121.10 (10(4), 10(6), 5 x 10(7), or 10(9) PFU), AdNull (5 x 10(7) or 10(9) PFU), or saline. Toxicity was assessed by survival, blood analyses, and organ histology at 3 and 7 days after vector administration. A separate group of C57/BL6 mice received intravenous AdmVEGF164 (Ad vector encoding the murine VEGF164 cDNA), Ad(GV)VEGF121.10, AdNull (10(8) PFU each group), or saline to assess duration of expression and safety of a homologous transgene. All mice survived to sacrifice except for 40% of the mice in the highest (10(9) PFU; a dose more than 10(3)-fold higher by body weight than the efficacious dose in pigs) Ad(GV)VEGF121.10 dose group, which died on days 5-6 after vector administration. The only differences seen in the blood analyses between treated and control mice were in the very high Ad(GV)VEGF121.10 dose group (10(9) PFU), which demonstrated an anemia as well as an increase in
alkaline phosphatase
when compared with all other treatment groups. Hepatic VEGF levels by ELISA in AdmVEGF164-treated mice did not persist beyond 14 days after vector administration, suggesting that persistent expression of a homologous VEGF gene transferred with an Ad vector is not a significant safety risk. Although this is not a chronic toxicity study, these data demonstrate the safety of direct myocardial administration of Ad(GV)VEGF121.10, and support the potential use of this strategy to treat human myocardial ischemia.
...
PMID:Safety of direct myocardial administration of an adenovirus vector encoding vascular endothelial growth factor 121. 1036 64
In situ split-liver transplantation is a new surgical technique where the bipartition of a single liver allows procurement of a right graft (segments I, IV, V-VIII) for an adult recipient (75% of the total liver volume), and a left graft (segments II and III) for a child recipient. The present study was designed to assess the effects of
ischemia
-reperfusion on right grafts obtained by in situ split-liver transplantation. To this aim, hepatic glutathione and conventional plasmatic markers of allograft function (alanine and aspartate aminotransferase, total bilirubin, prothrombin time, lactate dehydrogenase, gamma-glutamyltranspeptidase, and
alkaline phosphatase
) were evaluated in four adult recipients. At the time of reperfusion, a marked glutathione decrease was found in the segment VI in three cases, whereas the amount of glutathione in segment IV was related to the duration of cold
ischemia
in all cases. Upon reperfusion, a marked increase in plasmatic alanine aminotransferase, aspartate aminotransferase, and lactate dehydrogenase was found. A recovery in prothrombin time was observed from the first day in three cases. An increasing trend in total bilirubin, gamma-glutamyltranspeptidase, and
alkaline phosphatase
was noted from the second day after transplant. This preliminary study suggests a possible relationship between the duration of cold
ischemia
, amount of glutathione in segment IV of the right graft, and the trend in plasmatic markers of allograft damage during in situ split-liver transplantation in adult recipients.
...
PMID:Effects of ischemia-reperfusion on hepatic glutathione and plasmatic markers of graft function during in situ split-liver transplantation in adult recipients. 1111 71
The aim of our work was to study the changes in activity, abundance and distribution of sodium, potassium-adenosine triphosphatase (Na+,K+-ATPase) in membranes of cortical tubular cells in an in vivo model of ischemic injury without reperfusion. Na+,K+-ATPase,
alkaline phosphatase
(AP) activities and their distribution in membranes isolated from renal cortex using a Percoll gradient were studied after different ischemic periods. Na+,K+-ATPase alpha-subunit protein abundance was analysed by Western-blot. Plasma urea and cortical adenosine 5' triphosphate (ATP) were also measured. In cortical homogenates 5 min of
ischemia
promoted a diminution in ATP content. Na+,K+-ATPase activity diminished after 40 min and AP after 100 min of
ischemia
. Na+,K+-ATPase activity in the Percoll gradient fractions after 5 min peaked at a higher density and was significantly decreased after 40 min. AP activity was decreased in typically enriched apical membranes after both times of
ischemia
. At each time studied Na+,K+-ATPase abundance was increased in cortical homogenates and membranes. Our results showed opposite effects of
ischemia
on Na+,K+-ATPase activity and abundance. Increased levels of Na+,K+-ATPase protein were observed. The enzyme would be rapidly delivered to membrane domains and become inactivated as
ischemia
persists.
...
PMID:Cortical Na+,K+-ATPase activity, abundance and distribution after in vivo renal ischemia without reperfusion in rats. 1152 37
Restitution of bronchial artery circulation might alter
ischemia
- reperfusion injury and improve organ function after lung transplantation. Weight-matched dogs underwent a left lung allotransplantation either with bronchial artery revascularization (BAR; n = 6) or as conventional lung transplantation (LTX; n = 6), to evaluate effects of BAR on lung cell function over a period of 5 h postischemically. Lactate dehydrogenase (LDH) and marker enzymes for pneumocytes type I (carboxypeptidase M [CPM], pneumocytes type II (
alkaline phosphatase
[AP]), and pulmonary endothelium (angiotensin-converting-enzyme [ACE]) were determined from bronchoalveolar lavage fluid. Donor lungs were preserved with Euro-Collins solution. Total ischemic time was kept at 6 h. CPM and LDH activities were significantly higher in both groups at 2 h and 4 h of reperfusion compared with control dogs (p < 0.01). AP and ACE activities in lavage after 2 h of reperfusion were significantly elevated in animals that underwent LTX (AP: 60 +/- 28 IU/L; ACE: 1.39 +/- 1.13 IU/L) compared with animals with BAR (AP: 33 +/- 29 IU/L; ACE: 0.35 +/- 0.6 IU/L; p < 0.05) and with control animals (AP: 13.58 +/- 11.0 IU/L; ACE: 0.06 +/- 0.14 IU/L; p < 0.01). According to these results, BAR protects pulmonary endothelium and type II pneumocytes in the early phase after lung transplantation and might have consequences for lung tissue in the long term.
...
PMID:Bronchial artery revascularization affects graft recovery after lung transplantation. 1179 Jun 58
Ocular
ischemia
resulting from perfusion disturbances may play a major role in initiation of glaucoma. Possibly secondary to
ischemia
autoimmunogenic events are activated in glaucoma patients with increased prevalence of systemic autoimmune diseases. The determination of potential molecular markers in blood leukocytes could be useful for early noninvasive diagnostics of glaucoma. Our study using subtractive hybridization showed altered gene expression in leukocytes of glaucoma patients in comparison to age and sex matched healthy subjects. Subtracted genes encoding lymphocyte IgE receptor (Fc epsilon RII/CD23), T cell-specific tyrosine kinase, thromboxan A2 receptor,
alkaline phosphatase
and Na(+)/K(+)-ATPase are differentially expressed in circulating leukocytes of glaucoma patients. These genes show expression profiles characteristic for adherent leukocytes which could be an important contributor to blood-brain barrier breakdown which has been found in glaucoma patients.
...
PMID:Molecular imaging of perfusion disturbances in glaucoma. 1237 50
The expression of fibronectin (FN), one of the extracellular matrix proteins, was studied in isolated renal proximal tubules in a in vivo rat model of unilateral renal ischemia without reperfusion. FN is involved in cell-extracellular matrix interactions and defective cell-extracellular matrix interactions have been hypothesized to contribute to ischemic renal failure. The expression of FN was investigated by reverse transcription-polymerase chain reaction (RT-PCR), Elisa and Western blot. Isolated proximal tubules from control and post-ischemic rat kidneys were used. ATP, intracellular calcium content, and
alkaline phosphatase
were also measured to describe the effects associated to 40 min of
ischemia
. Control tubules expressed FN. Forty minutes of
ischemia
promoted diminished ATP levels and phosphatase alkaline activity, and increased intracellular calcium in isolated proximal tubules. An increased abundance of FN was observed by ischemic tubules as compared with control tubules. To determine quantitatively the value of FN content, ELISA method was performed. The ischemic tubules also expressed higher amount of FN mRNA. Three amplification products were obtained from both ischemic and control proximal tubular cDNA. The relative amounts of each of the obtained products were the same, strongly suggesting that the augmentation of the FN gene transcription during
ischemia
is not associated to a modification in the splicing pattern. Moreover, this expression is increased after 40 min of
ischemia
, not followed by reperfusion.
...
PMID:Fibronectin expression in proximal tubules from ischemic rat kidneys without reperfusion. 1248 21
To determine whether c-Fos and c-Jun are involved in the repair of small intestinal mucosa after
ischemia
-reperfusion (I/R), we investigated the mechanism of regeneration following acute I/R injury in rats by evaluating changes in DNA synthesis, fractional synthesis rate (FSR) of proteins, and
alkaline phosphatase
(
ALP
) activity. Furthermore, we examined the sequential expression of c-Fos and c-Jun using western blot analysis and immunohistochemical staining. Proliferating cell nuclear antigen (PCNA) labeling index (LI) demonstrated that the LI of the I/R group at 2 and 6 hr after reperfusion was significantly higher than that of the controls. Statistically significant differences were found between the FSRs of the I/R group and the corresponding conventional group at 2, 6, and 12 hr. The expression of c-Fos and c-Jun proteins increased markedly after I/R and these proteins decreased with time. The levels of
ALP
in the I/R group were significantly decreased at 2 and 6 hr after reperfusion compared to controls. These results indicate that c-Fos and c-Jun play a central role in the repair process that results in complete restoration of intestinal mucosal function after I/R.
...
PMID:Regeneration of small intestinal mucosa after acute ischemia-reperfusion injury. 1249 89
To elucidate the sequence of early events in the increase in capillarity caused by reperfusion following transient coronary occlusion, the time course of expression of proliferating cell nuclear antigen (PCNA) was studied immunohistochemically in rat hearts subjected to different periods of reperfusion after a 3 minute occlusion. Twenty-one male Wistar rats were killed after different periods of reperfusion following occlusion of the coronary artery for 3 minutes. The left ventricles were removed and paired serial sections were treated immunohistochemically for PCNA or stained to show the enzymes characteristic of the arteriolar, intermediate and venular portions of the capillary bed. The time course of PCNA expression, and its distribution in relation to the different portions, was examined. An increase in PCNA-expressing nuclei was found at 24 hours after the start of reperfusion; numbers reached a maximum between 72 and 96 hours, and at 168 hours had decreased again. The majority of PCNA-expressing elements were localized to the dipeptidylpeptidase IV-reactive (i.e. venular) capillary portions, with some in the intermediate and
alkaline phosphatase
-reactive (i.e. arteriolar) portions. The distribution of PCNA in the early reperfusion period suggests that angiogenesis after transient
ischemia
occurs mainly from the venular side of the capillary bed, with some contribution from intermediate and arteriolar capillary portions.
...
PMID:Coronary ischemia/reperfusion increases proliferating cell nuclear antigen in vascular endothelial cells in rat hearts. 1254 69
The aim of this study was to quantify the expression of E-selectin, intercellular cell adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1) in human umbilical vascular endothelial cells (HUVECs) exposed to anoxia/reoxygenation (A/R) in the presence or absence of an inflammatory context (0.1 IU/ml tumor necrosis factor-alpha [TNF-alpha]) and to investigate the effects of two different NADPH inhibitors, apocynin and diphenyleneiodonium (DPI), on the expression of the endothelial cell adhesion molecules. Confluent HUVECs were exposed to anoxia for 3 hours (100% N2), followed by a reoxygenation period of 4 hours. TNF-alpha at 0.1 IU/ml was added to the medium either under normoxic conditions for 7 hours (TNF-alpha) or just before the start of anoxia (A/R + TNF-alpha). Levels of E-selectin, VCAM-1, and ICAM-1 were quantified using specific monoclonal antibodies revealed by an
alkaline phosphatase
-labeled goat F(ab)'2 fragment against mouse IgG antibody and the fluorescent substrate Attophos. Adhesion experiments were also performed using calcein-labeled U937 leukocytes. HUVECs submitted to A/R overexpressed E-selectin but not VCAM-1 or ICAM-1, whereas TNF-alpha at 0.1 IU/ ml increased the expression of all three adhesion molecules. In endothelial cells subjected to A/R in the presence of TNF-alpha, a synergistic increase of E-selectin expression and a synergistic adhesion of U937 cells was noted. The NADPH oxidase inhibitors apocynin and DPI both decreased significantly the U937 adhesion and the E-selectin overexpression on HUVECs submitted to A/R, TNF-alpha, or A/R + TNF-alpha. These results suggest that E-selectin expression is implicated in the leukocyte adhesion to HUVECs caused by A/R in the presence or absence of an inflammatory context. NADPH oxidase appears to participate in the E-selectin overexpression on HUVECs subjected either to A/R and/or TNF-alpha, suggesting a major role of this enzyme in the
ischemia
/reperfusion syndrome.
...
PMID:Effect of NADPH oxidase inhibition on E-selectin expression induced by concomitant anoxia/reoxygenation and TNF-alpha. 1257 57
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